(1) Field of the Invention
The present invention relates to a method for optimization of an order for component mounting by a mounter. In particular, the invention relates to a method for optimization of an order of component mounting on a board that includes a plurality of patterns.
(2) Description of the Related Art
In a component mounting system where a plurality of mounters for mounting electronic components on a board, such as a printed board, are arranged in a mounting line, it is necessary to maintain line balance in such a way that a tact time for each mounter is even. In a component mounting system such as this, optimization of a mounting order is carried out, conventionally, by assigning components to be handled by each mounter based on (i) the tact time and (ii) the number of components for mounting allocated to each component (e.g., the conventional optimization explained in official publication of Japanese Laid-Open Patent Application No. 09-18199 and No. 10-209697).
In other words, as shown in FIG. 20, during the mounting of components onto a board 20, which includes a plurality of patterns 12, optimization of mounting order is carried out by having, among mounters 14a to 14d, a mounter located farther upstream in the process line (e.g., mounter 14a) mounting smaller components and a mounter located farther downstream in the process line (e.g., mounter 14d) mounting larger components.
During component mounting, each of the mounters 14a to 14d perform image recognition of board marks 16 set at corners of the board 20, and corrections are carried out for misalignment in the planar direction, rotational misalignment, expansion and contraction, and so on, of the board 20. Next, image recognition is performed for pattern marks 18 set on each pattern 12, and position determination of the patterns 12 is carried out. Subsequently, component mounting is carried out. In this manner, the performance of high precision position determination becomes possible through image recognition of the pattern marks 18 set on each pattern 12.
However, in the conventional component mounting system, each of the mounters 14a to 14d mounts components on all of the patterns 12 on the board 20. For this reason, each of the mounters is 14a to 14d must perform image recognition of pattern marks of all the patterns 12, requiring the consumption of much time before proceeding with component mounting. As such, there exists the problem of increased tact time for the component mounting system as a whole. For example, in the case where one hundred of the patterns 12 are included in one board 20 and there are two pattern marks 18 on each of the patterns 12, this means that two hundred (=100×2) of the pattern marks 18 are included in a single board 20. Each of the mounters 14a to 14d must perform image recognition of all these two hundred pattern marks 18.
Furthermore, as each of the mounters 14a to 14d carries out component mounting on all the patterns 12, the conventional component mounting system performs optimization so that mounting order is optimal in terms of the board as a whole. For this reason, the problem of taking long calculation times for performing optimization exists as component types and the number of mounting points, which are the subjects for optimization, increase.
In addition, in the case where there is a change in the number of mounters in the mounting line, the problem exists in which changes in line organization cannot be handled flexibly, with optimization having to be performed again from the start.
The present invention is conceived to resolve the issues described above, and has as an objective to provide a component mounting order optimization method for optimizing the order of component mounting so that tact time during component mounting is reduced.
Furthermore, the present invention also has as another objective to provide a component mounting order optimization method in which optimization of mounting order does not consume a lot of time.
In addition, the invention also has, as yet another objective, to provide a component mounting order optimization method that can flexibly respond to line organization modification due to a change in the number of mounters.